Just discovered: a small Traditionalist group in 1930s Thailand, described by Arthur Osborne in My Life and Quest (2001), available online.
Osborne was introduced to the works of Guénon by Martin Lings, who he knew in Gdynia, Poland before the Second World War. Lings gave him two books, one by Guénon and one by Gurdjieff's interpreter P. D. Ouspensky. It is interesting that Lings was recommending Ouspensky at that point.
Guénon's book, the Introduction générale à l'étude des doctrines hindoues had a great impact on Osborne, and Ouspensky did not. When he moved from Poland to Bangkok, Thailand, Osborne joined a small group of Traditionalists there, evidently all Europeans. He also became Muslim, joined an Indian dhikr group in Bangkok, and gave bayat to an unidentified shaykh in India in 1939, along with a number of other Bangkok Traditionalists .
It is not clear what happened to the Bangkok group. Osborne's final destination lay outside it. As the Second World War started and Thailand was threatened by the Japanese, his wife and daughter took refuge in India, where his wife was given "silent initiation" by the Hindu guru Ramana Maharshi, of whom Guénon did not approve. Osborne spent much of the war in an internment camp in Thailand, where he intended to devote himself to "prayer, meditation, incantations and reading the Arabic Quran," but as time passed found himself returning to "profane" life. After the war, he re-joined his family in India, and took Ramana Maharshi as his guru. He edited The collected works of Sri Ramana Maharshi, first published by Rider in 1959.
My thanks to B. H. for bringing Osborne's book to my attention.